1.1 This terminology covers definitions of technical terms used in the plastics industry. Terms that are generally understood or adequately defined in other readily available sources are not included. 1.2 When a term is used in an ASTM document for which Committee D20 is responsible it is included only when judged, after review, by Subcommittee D20.92 to be a generally usable term. 1.3 Definitions that are identical to those published by another standards body are identified with the abbreviation of the name of the organization; for example, IUPAC is the International Union of Pure and Applied Chemistry. 1.4 A definition is a single sentence with additional information included in discussion notes. It is reviewed every 5 years; the year of last review is appended. 1.5 For literature related to plastics terminology, see Appendix X1 .